1. Field of the Disclosure
The present disclosure relates to a sheath apparatus for positioning about a surgical instrument, and, in particular, to a disposable sheath and associated applicator for use with a radiation monitoring probe to preserve the sterility of the probe while performing diagnosis.
2. Description of the Related Art
Sheath apparatuses for maintaining the sterility of surgical instruments are well known in the art, particularly, in the field of endoscopy. For example, U.S. Pat. No. 4,878,485 to Adair discloses an endoscopic sheath including a rigid cylindrical housing for receiving the elongated endoscopic portion of an endoscope and a folded sleeve mounted adjacent the proximal end of the housing. The sleeve is extendable to cover the housing and the endoscope so as to prevent contamination of the endoscope during use. Other sheath apparatii having endoscopic application are disclosed in U.S. Pat. Nos. 4,852,551 to Opie; 4,869,238 to Opie; and 5,402,768 to Adair.
The above-described conventional sheath apparatii are suitable for their intended purposes in preserving the sterility of reusable endoscopes; however, these apparatii are deficient in certain respects, which deficiencies detract from their overall effectiveness and adaptability, particularly, for radiation monitoring probe instruments. Radiation monitoring probe instruments are utilized for detection of radioactively tagged (i.e., with radiopharmaceuticals) tissue for tissue diagnosis purposes. By way of example, one commercially available radiation monitoring probe is the RMD Gamma Guidance System manufactured by Radiation Monitoring Devices (RMD), Inc. of Watertown, Mass. This system includes a control unit and a probe for localizing and quantifying regions of increased radiopharmaceutical uptake in tissue. The probe generally includes a narrow shaft portion having an enlarged distal head which houses the electrical detection components for tissue diagnosis. An electrical cable connects the probe to the control unit. To date, there exists no sheath apparatus suitable for use with a radiation monitoring probe system of the afore described type.
Accordingly, the present disclosure relates to a sheath and associated applicator apparatus particularly adapted to be mounted to a radiation detection probe to preserve the probe from contamination fluids during use in diagnostic procedures thereby precluding the need to sterilize the probe components after each use. Generally, the sheath and applicator apparatus includes a flexible sheath member defining a longitudinal bore at least extending through the proximal end thereof dimensioned for reception of an elongated portion of a surgical instrument and an applicator mounted adjacent the proximal end of the sheath member for facilitating positioning of the sheath member about the elongated portion of the surgical instrument. The applicator includes a hollow tube portion defining an axial bore therethrough and a handle operatively connected to the tube portion. The tube portion is sufficient in length to support the sheath member in a folded condition thereof with a major portion of the length of the sheath member disposed about the tubular portion. The handle is dimensioned to be engaged by a surgeon and manipulated to extend the sheath member about the elongated portion of the instrument to an extended position with the elongated portion at least partially received within the longitudinal bore of the sheath member. Preferably, the sheath member defines an accordion configuration along a portion of its length to facilitate folding and positioning of the sheath member to the folded condition thereof supported by the applicator.
In a preferred embodiment, the sheath member defines a protruding distal tip portion with the distal tip portion defining a closed distal end face. The distal end face preferably has a generally smooth outer surface with no folds, creases, etc. to facilitate transmission of signals to and from the instrument. The sheath member may include a first proximal portion and a second distal portion with the first proximal portion defining a diameter greater than a diameter of the second distal portion. In the mounted position of the sheath member, the first proximal portion loses the cable extending to the probe while the second distal portion encloses the probe.